Several times now I saw new inexperienced symfony users getting confused by the Form::getErrors() method. The problem is the boolean $deep parameter with a false default value. Usually it goes like this:

1. $form->isValid() returns false. Wait what's wrong?
2. Oh I will call $form->getErrors() to see the problem!
3. It's empty. If there is no error why is the form not valid?

And here they get stuck for half an hour or more. Of course there is an error but you'll only see it with $form->getErrors(true). I confess that this took me a while to figure out as well when I was new to Symfony. Boolean parameters are just evil.

To remove this confusion I suggest to deprecate the getErrors method in favor of two new methods getAllErrors and getOwnErrors. I can send a PR if this change is wanted.